davinci: INTC: add support for TI cp_intc

Add support for Texas Instuments Common Platform Interrupt Controller
(cp_intc) used on DA830/OMAP-L137.

Signed-off-by: Steve Chen <schen@mvista.com>
Signed-off-by: Mark Greer <mgreer@mvista.com>
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 161 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/cp_intc.c b/arch/arm/mach-davinci/cp_intc.c
new file mode 100644
index 00000000000..96c8e97a7de
--- /dev/null
+++ b/arch/arm/mach-davinci/cp_intc.c
@@ -0,0 +1,161 @@
+/*
+ * TI Common Platform Interrupt Controller (cp_intc) driver
+ *
+ * Author: Steve Chen <schen@mvista.com>
+ * Copyright (C) 2008-2009, MontaVista Software, Inc. <source@mvista.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <mach/cp_intc.h>
+
+static void __iomem *cp_intc_base;
+
+static inline unsigned int cp_intc_read(unsigned offset)
+{
+        return __raw_readl(cp_intc_base + offset);
+}
+
+static inline void cp_intc_write(unsigned long value, unsigned offset)
+{
+        __raw_writel(value, cp_intc_base + offset);
+}
+
+static void cp_intc_ack_irq(unsigned int irq)
+{
+        cp_intc_write(irq, CP_INTC_SYS_STAT_IDX_CLR);
+}
+
+/* Disable interrupt */
+static void cp_intc_mask_irq(unsigned int irq)
+{
+        /* XXX don't know why we need to disable nIRQ here... */
+        cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_CLR);
+        cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_CLR);
+        cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET);
+}
+
+/* Enable interrupt */
+static void cp_intc_unmask_irq(unsigned int irq)
+{
+        cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_SET);
+}
+
+static int cp_intc_set_irq_type(unsigned int irq, unsigned int flow_type)
+{
+        unsigned reg            = BIT_WORD(irq);
+        unsigned mask           = BIT_MASK(irq);
+        unsigned polarity       = cp_intc_read(CP_INTC_SYS_POLARITY(reg));
+        unsigned type           = cp_intc_read(CP_INTC_SYS_TYPE(reg));
+
+        switch (flow_type) {
+        case IRQ_TYPE_EDGE_RISING:
+                polarity |= mask;
+                type |= mask;
+                break;
+        case IRQ_TYPE_EDGE_FALLING:
+                polarity &= ~mask;
+                type |= mask;
+                break;
+        case IRQ_TYPE_LEVEL_HIGH:
+                polarity |= mask;
+                type &= ~mask;
+                break;
+        case IRQ_TYPE_LEVEL_LOW:
+                polarity &= ~mask;
+                type &= ~mask;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        cp_intc_write(polarity, CP_INTC_SYS_POLARITY(reg));
+        cp_intc_write(type, CP_INTC_SYS_TYPE(reg));
+
+        return 0;
+}
+
+static struct irq_chip cp_intc_irq_chip = {
+        .name           = "cp_intc",
+        .ack            = cp_intc_ack_irq,
+        .mask           = cp_intc_mask_irq,
+        .unmask         = cp_intc_unmask_irq,
+        .set_type       = cp_intc_set_irq_type,
+};
+
+void __init cp_intc_init(void __iomem *base, unsigned short num_irq,
+                         u8 *irq_prio)
+{
+        unsigned num_reg        = BITS_TO_LONGS(num_irq);
+        int i;
+
+        cp_intc_base = base;
+
+        cp_intc_write(0, CP_INTC_GLOBAL_ENABLE);
+
+        /* Disable all host interrupts */
+        cp_intc_write(0, CP_INTC_HOST_ENABLE(0));
+
+        /* Disable system interrupts */
+        for (i = 0; i < num_reg; i++)
+                cp_intc_write(~0, CP_INTC_SYS_ENABLE_CLR(i));
+
+        /* Set to normal mode, no nesting, no priority hold */
+        cp_intc_write(0, CP_INTC_CTRL);
+        cp_intc_write(0, CP_INTC_HOST_CTRL);
+
+        /* Clear system interrupt status */
+        for (i = 0; i < num_reg; i++)
+                cp_intc_write(~0, CP_INTC_SYS_STAT_CLR(i));
+
+        /* Enable nIRQ (what about nFIQ?) */
+        cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET);
+
+        /*
+         * Priority is determined by host channel: lower channel number has
+         * higher priority i.e. channel 0 has highest priority and channel 31
+         * had the lowest priority.
+         */
+        num_reg = (num_irq + 3) >> 2;   /* 4 channels per register */
+        if (irq_prio) {
+                unsigned j, k;
+                u32 val;
+
+                for (k = i = 0; i < num_reg; i++) {
+                        for (val = j = 0; j < 4; j++, k++) {
+                                val >>= 8;
+                                if (k < num_irq)
+                                        val |= irq_prio[k] << 24;
+                        }
+
+                        cp_intc_write(val, CP_INTC_CHAN_MAP(i));
+                }
+        } else  {
+                /*
+                 * Default everything to channel 15 if priority not specified.
+                 * Note that channel 0-1 are mapped to nFIQ and channels 2-31
+                 * are mapped to nIRQ.
+                 */
+                for (i = 0; i < num_reg; i++)
+                        cp_intc_write(0x0f0f0f0f, CP_INTC_CHAN_MAP(i));
+        }
+
+        /* Set up genirq dispatching for cp_intc */
+        for (i = 0; i < num_irq; i++) {
+                set_irq_chip(i, &cp_intc_irq_chip);
+                set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
+                set_irq_handler(i, handle_edge_irq);
+        }
+
+        /* Enable global interrupt */
+        cp_intc_write(1, CP_INTC_GLOBAL_ENABLE);
+}